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Please kindly understand that the Outlook tag here we mainly focus on general issues about Outlook desktop client.
Currently, I'm afraid there is no official download channel to get Office for Mac 2016. Because the official support for Office 2016 has been removed. In addition, Office 2016 connectivity to Microsoft 365 has also been discontinued in October 2023. For the security of your account and for better support, it is recommended that you upgrade your Oulook version and operating system.
Ref: Deployment options for admins for Office for Mac - Deploy Office | Microsoft Learn&End of support for Office 2016 for Mac - Microsoft Support.
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